1. Field of the Invention
The present invention relates generally to electrocardiograph systems, and more particularly to an electrode connector for electrically connecting a signal-conducting leadwire from an electrocardiograph patient monitoring system to a biomedical electrode.
2. Description of Related Art
The electrocardiogram (ECG or EKG) system is a common diagnostic tool that measures and records the electrical activity of the heart. An ECG system produces a graphic representation of electrical activity called an electrocardiograph, which records the electrical voltage in the heart in the form of a continuous strip graph. It is the prime tool in cardiac electrophysiology, and has a prime function in screening and diagnosis of cardiovascular diseases. Interpretation of these details allows diagnosis of a wide range of heart conditions.
The ECG has a wide variety of uses including: (1) determining whether the heart is performing normally or suffering from abnormalities; (2) indicating acute or previous damage to heart muscle (heart attack) or ischaemia of heart muscle (angina); (3) detecting potassium, calcium, magnesium and other electrolyte disturbances; (4) allowing the detection of conduction abnormalities (heart blocks and bundle branch blocks); (5) as a screening tool for ischaemic heart disease during an exercise tolerance test; (6) providing information on the physical condition of the heart; and (7) providing a tool to diagnose or suggest non-cardiac disease.
An ECG is constructed by measuring electrical potential between various points of the body using a galvanometer. In the United States, leads I, II and III are measured over the limbs: I is from the right to the left arm, II is from the right arm to the left leg and III is from the left arm to the left leg. From this, the imaginary point V is constructed, which is located centrally in the chest above the heart. The other nine leads are derived from potential between this point and the three limb leads (aVR, aVL and aVF) and the six precordial leads (V1-6). Therefore, there may be as many as twelve leads in total.
A typical ECG system relies on electrodes placed on a patient in specific locations to detect electrical impulses generated by the heart during each beat. Electrical impulses detected by the electrodes are communicated to an ECG monitor via a plurality of leadwires, each of which terminated with an electrically conductive electrode connector that is physically connected to one of said electrodes so as to be in electrical communication therewith. The electric signals generated by the heart are weak, typically from 0.5 mV to 2.0 mV.
There are two primary ways in which electrode connectors attach to the studs of biomedical patient electrodes, namely by pinch connection or snap/press connection. Certain electrode connectors are designed for pinch connection. An example of such an electrode connector is found in U.S. Pat. No. 4,178,052, issued to Ekbom, which discloses an open ended electrode connector adapted to pinch the stud of a patient electrode between a pair of jaws. Open ended connectors, however, are burdened with a significant disadvantage, namely a tendency to snare or snag leadwires that happen to come between the opening between the jaws. When wires accidently become snagged, the connector and/or the entire connector and electrode assembly can be unknowingly dislodged from the patient. In an effort to overcome that disadvantage, “closed end” electrode connectors have been developed. For example, U.S. Pat. No. 4,390,223, issued to Zenkich, discloses a closed end electrode connector. Another category of electrode connectors is referred to as the “snap” connectors. These connectors snap on to the stud of the electrode by application of a downward pressure. An example of such an electrode connector is found in U.S. Pat. No. 4,671,591, issued to Archer. It has been found that pinch connectors are preferred in certain healthcare environments while snap connectors are preferred in other environments. Accordingly, there exists a need for an improved electrode connector that maximizes the advantages of both snap and pinch connectors.
Further, conventional ECG electrodes, connectors, and leadwires are often constructed with metal components that show up clearly on X-rays and other imaging procedures. When those components show-up on X-Rays they can complicate medical procedures by obscuring vital organs and other anatomical structures. Accordingly, transparency to hospital imaging systems, such as X-ray or fluoroscopes, is desirable in many medical procedures so that the patient's body may be X-rayed without removing the flexible leadwires so that the patient's bio-signals may be recorded without interruption.
Although several efforts have been directed towards developing radiolucent ECG components in the past, none of these efforts have heretofore proven successful. U.S. Pat. No. 5,356,428, issued to Way, discloses a radiolucent electrode that replaces conventional foil backing with an expanded foil backing formed by a mesh structure of metal wires that produce a low enough attenuation of X-irradiation such that body structures may be visualized through the backing without significant degradation. U.S. Pat. No. 4,800,887, issued to Shigeta et al., discloses an X-ray transparent electrode fabricated with graphite. U.S. Pat. No. 5,366,497, issued to Ilvento et al., discloses a radiolucent electrode connected to otherwise conventional insulated metal leadwire. U.S. Pat. Nos. 7,860,557 and 7,933,642, each issued to Istvan et al., disclose a radiolucent chest assembly for a wireless monitoring system.
A further shortcoming found with electrode connectors relates to poor electrical contact between the signal conducting stud found on the biomedical electrode and the conducting element. Most electrode connectors include a flat, electrically conducting metal plate that defines an opening or aperture which receives the stud of a biomedical patient electrode. The poor electrical connection is due to the minimal contact between the peripheral edge of the aperture with the outer surface of the electrode stud.
Accordingly, there further exists a need for advancements in the field of electrode connectors for EKG/ECG systems, including improved electrical connections, and improved radiolucent characteristics.